"Table 2" of "Global baryon number conservation encoded in net-proton fluctuations measured in Pb–Pb collisions at sNN=2.76 TeV"

CERN-LHC. Experimental results are presented on event-by-event net-proton fluctuation measurements in Pb--Pb collisions at $\sqrt{s_{\mathrm {NN}}} = 2.76$~TeV, recorded by the ALICE detector at the CERN LHC. These measurements have as their ultimate goal an experimental test of Lattice QCD (LQCD) predictions on second and higher order cumulants of net-baryon distributions to search for critical behavior near the QCD phase boundary. Before confronting them with LQCD predictions, account has to be taken of correlations stemming from baryon number conservation as well as fluctuations of participating nucleons. Both effects influence the experimental measurements and are usually not considered in theoretical calculations. For the first time, it is shown that event-by-event baryon number conservation leads to subtle long-range correlations arising from very early interactions in the collisions.

欧洲核子研究中心大型强子对撞机（CERN-LHC）。本研究展示了由该装置上的ALICE探测器（ALICE detector）采集的、质心系能量√s_NN=2.76太电子伏特（TeV）的铅核-铅核碰撞中逐事件净质子涨落的实验测量结果。本次测量的终极目标是通过实验检验格点量子色动力学（Lattice QCD，简称LQCD）对净重子分布二阶及更高阶累积量的预言，以探寻量子色动力学（QCD）相边界附近的临界行为。在将实验测量结果与格点量子色动力学预言进行比对前，需考虑由重子数守恒以及参与核子涨落所引发的关联效应；这两种效应均会对实验测量产生影响，而理论计算中通常未将其纳入考量。本研究首次证实，逐事件重子数守恒会由碰撞极早期的相互作用引发微妙的长程关联。